A PBX (private branch exchange) is a telephone system within an enterprise that switches calls between enterprise users on local lines while allowing all users to share a certain number of external phone lines. The principal purpose of a PBX is to avoid the cost of requiring a line for each enterprise user to a telephone central office. The PBX is owned and operated by the enterprise rather than the telephone company (which may be a supplier or service provider, however). Originally, PBXs used analog technology to switch calls between users and the PSTN (public switch telephone network). More recently, digital technology has been used to implement PBX functionality (digital signals are converted to analog for outside calls on the local loop).
Modern day digital PBXs provide may enhanced features, including scheduled events such as wakeup calls or call forwarding. By scheduling a telephony event, such as a wakeup call or automatic call forwarding, the user does not have to worry about over-sleeping or being disturbed during certain hours, as but two examples. However, when a user is using his or her phone, or has used the phone during execution of the prescheduled event or feature etc., the prescheduled event or feature may no longer be appropriate. For example, in a hotel/motel wake up call system, it may not make sense for a wakeup call to be sent to a user 10 minutes after the individual has just answered a different call, made a new call, or gone off-hook for some other reason (prior to the scheduled wakeup call). It would be advantageous if the behaviour of the wakeup call feature could be adaptable based on the activity of the user's phone within a configurable time frame.
In previous applications, canceling of an operator or attendant invoked feature typically occurs from a central administrative position (i.e. Attendant or operator console) either through a feature key selection or command invocation from a PC or a central console.